change_pass.vb

图书管理系统最新的

Imports System.Data.SqlClient

Public Class change_pass
    Inherits System.Windows.Forms.Form
    Dim cn As New SqlConnection("server=localhost;database=lms;uid=sa;password=;")
    Dim da As SqlDataAdapter
    Dim ds As DataSet
#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents lbl_name As System.Windows.Forms.Label
    Friend WithEvents lbl_studid As System.Windows.Forms.Label
    Friend WithEvents Label6 As System.Windows.Forms.Label
    Friend WithEvents txt_newpass As System.Windows.Forms.TextBox
    Friend WithEvents txt_oldpass As System.Windows.Forms.TextBox
    Friend WithEvents txt_confirm As System.Windows.Forms.TextBox
    Friend WithEvents btn_ok As System.Windows.Forms.Button
    Friend WithEvents btn_close As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.btn_ok = New System.Windows.Forms.Button
        Me.btn_close = New System.Windows.Forms.Button
        Me.lbl_name = New System.Windows.Forms.Label
        Me.txt_newpass = New System.Windows.Forms.TextBox
        Me.lbl_studid = New System.Windows.Forms.Label
        Me.txt_oldpass = New System.Windows.Forms.TextBox
        Me.Label6 = New System.Windows.Forms.Label
        Me.txt_confirm = New System.Windows.Forms.TextBox
        Me.SuspendLayout()
        '
        'btn_ok
        '
        Me.btn_ok.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.btn_ok.ForeColor = System.Drawing.SystemColors.ControlText
        Me.btn_ok.Location = New System.Drawing.Point(80, 128)
        Me.btn_ok.Name = "btn_ok"
        Me.btn_ok.Size = New System.Drawing.Size(56, 23)
        Me.btn_ok.TabIndex = 3
        Me.btn_ok.Text = "&OK"
        '
        'btn_close
        '
        Me.btn_close.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.btn_close.ForeColor = System.Drawing.SystemColors.ControlText
        Me.btn_close.Location = New System.Drawing.Point(152, 128)
        Me.btn_close.Name = "btn_close"
        Me.btn_close.Size = New System.Drawing.Size(56, 23)
        Me.btn_close.TabIndex = 4
        Me.btn_close.Text = "&Cancel"
        '
        'lbl_name
        '
        Me.lbl_name.AutoSize = True
        Me.lbl_name.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.lbl_name.ForeColor = System.Drawing.Color.Navy
        Me.lbl_name.Location = New System.Drawing.Point(19, 57)
        Me.lbl_name.Name = "lbl_name"
        Me.lbl_name.Size = New System.Drawing.Size(95, 17)
        Me.lbl_name.TabIndex = 28
        Me.lbl_name.Text = "New Password :"
        '
        'txt_newpass
        '
        Me.txt_newpass.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.txt_newpass.Location = New System.Drawing.Point(146, 53)
        Me.txt_newpass.MaxLength = 10
        Me.txt_newpass.Name = "txt_newpass"
        Me.txt_newpass.PasswordChar = Microsoft.VisualBasic.ChrW(42)
        Me.txt_newpass.Size = New System.Drawing.Size(128, 21)
        Me.txt_newpass.TabIndex = 1
        Me.txt_newpass.Text = ""
        '
        'lbl_studid
        '
        Me.lbl_studid.AutoSize = True
        Me.lbl_studid.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.lbl_studid.ForeColor = System.Drawing.Color.Navy
        Me.lbl_studid.Location = New System.Drawing.Point(19, 25)
        Me.lbl_studid.Name = "lbl_studid"
        Me.lbl_studid.Size = New System.Drawing.Size(89, 17)
        Me.lbl_studid.TabIndex = 25
        Me.lbl_studid.Text = "Old Password :"
        '
        'txt_oldpass
        '
        Me.txt_oldpass.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.txt_oldpass.Location = New System.Drawing.Point(146, 21)
        Me.txt_oldpass.MaxLength = 10
        Me.txt_oldpass.Name = "txt_oldpass"
        Me.txt_oldpass.PasswordChar = Microsoft.VisualBasic.ChrW(42)
        Me.txt_oldpass.Size = New System.Drawing.Size(128, 21)
        Me.txt_oldpass.TabIndex = 0
        Me.txt_oldpass.Text = ""
        '
        'Label6
        '
        Me.Label6.AutoSize = True
        Me.Label6.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label6.ForeColor = System.Drawing.Color.Navy
        Me.Label6.Location = New System.Drawing.Point(19, 89)
        Me.Label6.Name = "Label6"
        Me.Label6.Size = New System.Drawing.Size(120, 17)
        Me.Label6.TabIndex = 33
        Me.Label6.Text = "Re-enter Password :"
        '
        'txt_confirm
        '
        Me.txt_confirm.Font = New System.Drawing.Font("Tahoma", 8.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.txt_confirm.Location = New System.Drawing.Point(146, 85)
        Me.txt_confirm.MaxLength = 10
        Me.txt_confirm.Name = "txt_confirm"
        Me.txt_confirm.PasswordChar = Microsoft.VisualBasic.ChrW(42)
        Me.txt_confirm.Size = New System.Drawing.Size(128, 21)
        Me.txt_confirm.TabIndex = 2
        Me.txt_confirm.Text = ""
        '
        'change_pass
        '
        Me.AcceptButton = Me.btn_ok
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.BackColor = System.Drawing.Color.Silver
        Me.ClientSize = New System.Drawing.Size(296, 173)
        Me.Controls.Add(Me.Label6)
        Me.Controls.Add(Me.txt_confirm)
        Me.Controls.Add(Me.btn_ok)
        Me.Controls.Add(Me.btn_close)
        Me.Controls.Add(Me.lbl_name)
        Me.Controls.Add(Me.txt_newpass)
        Me.Controls.Add(Me.lbl_studid)
        Me.Controls.Add(Me.txt_oldpass)
        Me.MaximizeBox = False
        Me.MinimizeBox = False
        Me.Name = "change_pass"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "Change Password"
        Me.ResumeLayout(False)

    End Sub

#End Region


    Private Sub btn_ok_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_ok.Click
        Try
            'all passwords are provided
            If txt_oldpass.Text <> "" AndAlso txt_newpass.Text <> "" AndAlso txt_confirm.Text <> "" Then
                update_pass()
            Else 'one or more passwords is not provided 
                MessageBox.Show("All field are mandatory to fill.", "Exception", MessageBoxButtons.OK, MessageBoxIcon.Warning)
                txt_oldpass.Focus()
            End If


        Catch err As System.Exception
            MessageBox.Show(err.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        End Try
    End Sub

    Private Function validate_old_password() As Integer

        Try
            da = New SqlDataAdapter("select Pwd from user_auth", cn)
            ds = New DataSet

            'fetching user information from database
            da.Fill(ds, "user_auth")

            'checking password
            If txt_oldpass.Text = ds.Tables(0).Rows(0)(0) Then
                Return 1
            Else
                Return 0
            End If


        Catch ers As SqlException
            MessageBox.Show(ers.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        Catch err As System.Exception
            MessageBox.Show(err.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        Finally

            'dereferencing objects
            da = Nothing
            ds = Nothing


        End Try

    End Function

    Sub update_pass()
        Try

            Dim i As Short

            i = validate_old_password() 'checking old password

            If i = 1 Then 'old password matches.

                If txt_newpass.Text = txt_confirm.Text Then 'new passwords are same
                    Dim cmd As New SqlCommand
                    cmd.CommandText = "update user_auth set pwd='" & txt_newpass.Text & "' where Usr_name='Librarian'"
                    cmd.Connection = cn
                    cmd.ExecuteNonQuery()
                    cmd = Nothing
                    MessageBox.Show("Passwords successfully changed !!!", "LMS", MessageBoxButtons.OK, MessageBoxIcon.Information)
                    Me.Close()

                Else 'new passwords are different
                    MessageBox.Show("New passwords do not match.", "LMS", MessageBoxButtons.OK, MessageBoxIcon.Error)
                End If

            Else 'ols password does not match
                MessageBox.Show("Old password does not match.", "LMS", MessageBoxButtons.OK, MessageBoxIcon.Error)
            End If

        Catch ers As SqlException
            MessageBox.Show(ers.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        Catch err As System.Exception
            MessageBox.Show(err.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)


        End Try

    End Sub
    Private Sub btn_close_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_close.Click
        Me.Close()
    End Sub

    Private Sub txt_newpass_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txt_newpass.GotFocus
        txt_newpass.SelectAll()
    End Sub
    Private Sub txt_oldpass_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txt_oldpass.GotFocus
        txt_oldpass.SelectAll()
    End Sub

    Private Sub txt_confirm_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txt_confirm.GotFocus
        txt_confirm.SelectAll()
    End Sub

    Private Sub change_pass_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            cn.Open()
        Catch ex As SqlException
            MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)
            Me.Close()
        End Try
    End Sub

    Private Sub change_pass_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
        cn.Close()
    End Sub
End Class